The clinical implication of the number of lymph nodes harvested during sentinel lymph node biopsy and its effects on survival outcome in patients with node-negative breast cancer

•Sentinel lymph node biopsy (SLNB) is a standard axillary procedure for early breast cancer.•The optimal number of SLNs to be harvested during SLNB is not well established.•The current study reviewed 613 patients to define the optimal number of SLNs.•Survival analyses revealed that patients with only 1 harvested lymph node (LN) show poorer survival than those with ≥2 LNs.•Removing 2 LNs during SLNB may be optimal.

BackgroundThe optimal number of sentinel lymph nodes (SLN) that need to be harvested to achieve favorable survival outcome during a SLN biopsy (SLNB) has not yet been established.MethodsSix hundred and thirteen patients with clinically node-negative breast cancer who underwent SLNB were reviewed. Survival outcomes according to the number of total harvested lymph nodes (THLNs), defined as the sum of enumerated SLNs and non-SLNs were analyzed.ResultsPatients with only 1 THLN showed lower recurrence-free survival (RFS) as compared to those with ≥2 THLNs (p = 0.049). In multivariate analysis, only 1 THLN was associated with poor RFS (HR = 2.711; p = 0.029).ConclusionsRemoving at least 2 lymph nodes during SLNB may be acceptable. Harvesting only 1 lymph node should be undertaken cautiously because of false negative results and increasing the subsequent recurrence rate.